Understanding GI (Glycemic Index)

Eating low GI foods will help maintain your energy levels throughout the day and has some other great health benefits too.

What is Glycemic Index?

Every time we eat a carbohydrate food, such as pasta, potatoes, yogurt, cereal or fruit, our bodies convert carbohydrate to glucose for energy. Once upon a time we thought all carbohydrate foods were the same. We now know there is a difference in how quickly they are digested by the body. The Glycemic Index (GI) is a measure of how quickly these carbohydrate-rich foods are broken down into glucose and raise our blood glucose levels. Foods are ranked out of 100, with slowly digested carbohydrates classified as low GI (55 or less) and quickly digested carbohydrates as high GI (70 or more).

Benefits of eating the low-GI way

Eating high-GI foods can lead to energy ups and downs as the glucose reaches your bloodstream quickly (i.e. the sugar hit), but it doesn’t last for long. You could find yourself reaching for more snacks to bump up your energy levels again. Low-GI foods give you more steady energy levels across the day, helping to avoid the ‘slump’ you may find you aren’t as hungry. “In fact, there is very strong evidence that healthy low-GI diets are the most effective way of losing body weight, and more importantly, body fat,” says dietician and author Alan Barclay. “There is growing evidence that low-GI diets can help prevent type 2 diabetes, heart disease and certain cancers,” he says.

How can I tell the GI of a food?

Not all carbohydrate foods have their GI measured. Foods that carry the GI logo have been tested and meet the criteria set out by the GI Symbol team. So lookout for the GI logo in the supermarket.

How can I lower the GI of my diet?

Getting the benefits from low-GI eating is easy! An easy way to lower the GI of your diet is to include one low-GI food at each meal and snack – for example, adding a low-GI food like baked beans to a high-GI food like potato will help to reduce the overall GI of the meal. It is important to remember that portion size counts. Just because it’s low-GI, doesn’t mean you can eat as much as you like. Eating too many kilojoules, even if they are from low GI carbohydrates, can still lead to weight gain.

Aren’t all carbs bad for me?

There are plenty of myths out there about carbohydrates. The most common one is that carbohydrates are fattening. Protein, fat and carbohydrates all contain kilojoules, and if you eat too much of any of them without burning the energy, you can gain weight. Carbohydrates are actually the preferred energy source for your brain and working muscles, plus they have half the energy of fat. So include plenty of good quality carbs in your diet like wholegrain breads and cereals, fruit and reduced-fat dairy, but remember to watch your overall kilojoule intake as well.